Abstract

A new hydrolysis process of methyl glycolate(MG) to glycolic acid(GA) was studied in this thesis in order to tackle the prevalent problems in the traditional glycolic acid industry production process, such as pollution, serious corrosion and complicated final treatment. And the feasibility of introducing the catalytic distillation technology in the process was also studied.Under the condition of no catalysts, the effects of initial water-MG molar ratio and reaction temperature on the hydrolysis of methyl glycolate were investigated to find out the boundary conditions. Six different resins were compared in terms of the catalytic activity, and the result showed that001×7ion exchange resin was an effective catalyst for this reaction. And then the kinetics of hydrolysis of MG over001×7ion exchange resin was studied. Then the feasibility of using the catalytic distillation technology in the hydrolysis of MG was studied, and the effects of the initial water-MG molar ratio, the tower heating power, the reflux ratio and the operating pressure were investigated.Experimental results showed that without catalysts the final conversion of MG increased when the initial mole ratio increased; and when the temperature increased, the hydrolysis rate increased significantly, but the final conversion of MG had no obvious change. In order to avoid the by-product, the value of initial molar ratio should be greater than4:1and the temperature should be less than100℃. The kinetics of the hydrolysis of MG over001×7resin was evaluated by the use of the pseudohomogeneous model as follow:The experimental data were correlated by the model, the kinetics parameters were as follows:k0=70.901mol/(g min), E=27.614kJ/mol, c=0.41, d=0.12,e=0.10,f=2.93。Conclusions can be drawn from the research of the batch reactive distillation that the final conversion of MG could be promoted significantly by using this technology. When the value of initial molar ratio was greater than10:1, the operating pressure was about50KPa, the tower heating power was around30W and the reflux ratio is less than2, the conversion of MG could be almost100%in240minutes. The throughput capacity increased when the initial molar ratio or the tower heating power increased.